The Impact of Low Heat Load and Activated Carbon Treatment of Second Wort on Beer Taste and Flavor Stability

Masaaki Yano^1,2, Werner Back² and Martin Krottenthaler²
¹ Masaaki Yano, Planning section, Technology Development Department, Production Division, Kirin Brewery Co., Ltd., 2-10, Shinkawa, Chuo-ku, Tokyo, 104-0033, Japan.
² Technische Universität München, Lehrstuhl für Technologie der Brauerei I, Weihenstephaner Steig 20, 85354 Freising, Germany.
³ Corresponding author. E-mail: myano@kirin.co.jp

J. Inst. Brew. 114(4), 357–364, 2008 | VIEW ARTICLE

ABSTRACT
There is a vast repository of knowledge regarding improving beer taste stability via wort boiling. However, as far as we are aware, there are few reports dealing with taste stability improvement in terms of quality characteristics by boiling, under proper conditions, the first wort and second worts separately. In this study, more than 50 brews in a pilot scale brewing facility were conducted to investigate suitable boiling conditions for first and second worts. When the second wort (i.e., the last 10% of the total filtered wort) was kept under a low heat load atmosphere (78°C), casted to the boiling first wort, and then re-boiled for 10 min, the produced beer exhibited no significant differences compared to that of the general beer in terms of taste stability. However, when an adsorbent (bentonite, silica gel, activated carbon or PVPP) was individually added to the second wort and the same boiling procedure was performed, the oxidized flavour of the forced aged beer, treated with activated carbon, significantly decreased, compared to that of the general brew (level of significance α = 0.01). The data from the chemical analysis and fermentation behavior are presented.

Key words:
Activated carbon, adsorbent, brewing, flavor stability, heat load, second wort, wort boiling.